Sludge incineration facility and sludge incineration method

Abstract

To provide a sludge incineration facility capable of reducing a scale of a dryer (treatment amount or the number of units) necessary for drying sludge supplied to a stoker type incinerator and a sludge incineration method.SOLUTION: A sludge incineration facility 100 includes a reciprocating fire grate 12M, a dry body feeding device 2, a dehydrated sludge feeding device 3, a dry body sensor 4, and a control device 9. The fire grate 12M reciprocates in a direction from an upstream side toward a downstream side. The dry body feeding device 2 feeds a dry body DB to the fire grate 12M. The dehydrated sludge feeding device 3 feeds dehydrated sludge DS onto the dry body DB fed to the fire grate 12M. The dry body sensor 4 measures an amount of the dry body DB fed to the fire grate 12M. The control device 9 controls the dehydrated sludge feeding device 3 so as to feed the dehydrated sludge DS when the dry body sensor 4 measures the amount of the dry body DB stacked on the fire grate 12M. The fire grate 12M sends out the dry body DB on which the dehydrated sludge DS is stacked to a combustion region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sludge incineration facility for incinerating sludge and a sludge incineration method. [Background technology]

[0002] Conventionally, sewage sludge generated from sewage introduced into a sewage treatment plant has a moisture content of 98 to 99%, so when incinerating it, it is dehydrated using a dehydrator such as a centrifugal dehydrator or a filter press dehydrator to produce dehydrated sludge, and the dehydrated sludge is dried in a dryer to produce a dry cake with a moisture content of 35 to 40% before being transported to an incineration facility. As an example of such an incineration facility, a stoker-type incinerator as described in Patent Document 1 is known. In a stoker-type incinerator as described in Patent Document 1, a retractable fire grate sends out sludge while completely combusting it with air supplied from under the grate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-257131 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the moisture content of dewatered sludge is usually 76 to 80%, a large-scale drying device is required to dry the dewatered sludge to a moisture content of 35 to 40%, as described in Patent Document 1, which poses a problem of high construction costs. In addition, since dewatered sludge is highly adhesive, if it is supplied to an incinerator in an insufficiently dried state, it may adhere to the fire grate and become impossible to transport, or it may be compacted by the fire grate and turn into large lumps that make it difficult to completely combust in the incinerator.

[0005] Therefore, an object of the present invention is to reduce the scale (treatment volume or number) of drying devices in a stoker-type incinerator. [Means for solving the problem]

[0006] The sludge incineration equipment of the present invention is a sludge incineration equipment that sends out sludge from upstream to downstream and incinerates the sludge, and is equipped with a grate that moves back and forth in a direction from upstream to downstream, a dried body supplying device that supplies dried bodies to the grate, a dehydrated sludge supplying device that supplies dehydrated sludge having a higher moisture content than the dried body on top of the dried body supplied to the grate, a dried body sensor that measures the amount of dried bodies supplied to the grate, and a control device that controls the dehydrated sludge supplying device to supply the dehydrated sludge when the dried body sensor measures the amount of dried bodies piled on the grate, and is characterized in that the grate sends the dried bodies with the dehydrated sludge piled up thereon to an area where the dried bodies and the dehydrated sludge are burned.

[0007] In addition, the sludge incineration method of the present invention is a sludge incineration method in which a retractable grate sends sludge from upstream to downstream while incinerating the sludge with air supplied from below the grate, and is characterized by comprising the steps of: supplying a dried body; supplying dehydrated sludge having a higher moisture content than the dried body on top of the dried body; sending the dried body with the dehydrated sludge piled on it from upstream to downstream; and burning the dried body and the dehydrated sludge sent downstream. Effect of the Invention

[0008] According to the sludge incineration facility and the sludge incineration method of the present invention, it is possible to reduce the scale (treatment volume or number) of the drying devices used to dry the sludge to be supplied to the stoker-type incinerator. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a sludge incineration facility according to a first embodiment. [Diagram 2] FIG. 1 is a schematic cross-sectional view of an incinerator as viewed from downstream, showing an example of a distributed feeder having multiple screw feeders. [Diagram 3]FIG. 2 is a schematic cross-sectional view of a combustion furnace as viewed from downstream, showing an example of a dispersion supply device as a molding machine. [Figure 4] FIG. 13 is a diagram showing an example in which a dry matter sensor is a first supply amount recorder and a dewatered sludge sensor is a second supply amount recorder. [Diagram 5] FIG. 2 is a schematic diagram showing a drying stage grate directing dried sludge downstream. [Figure 6] FIG. 1 is a schematic diagram showing a grate conveying dry sludge loaded with dewatered sludge. [Figure 7] 4 is a flow chart showing the first part of the flow of a sludge incineration method in the sludge incineration facility according to the first embodiment. [Figure 8] 4 is a flow chart showing the latter part of the flow of the sludge incineration method in the sludge incineration facility according to the first embodiment. [Figure 9] FIG. 1 is a schematic diagram of a sludge incineration facility according to a second embodiment. [Figure 10] 10 is a flowchart showing the flow of a sludge incineration method in a sludge incineration facility according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an outline of a sludge incineration plant 100 according to a first embodiment of the present invention, a sludge incineration plant 200 according to a second embodiment, and a sludge incineration method will be described with reference to FIG. 1 and FIG.

[0011] The sludge incineration facilities 100, 200 incinerate materials to be incinerated in a stoker-type incinerator 1 (hereinafter, incinerator 1). The materials to be incinerated are sent from the upstream to the downstream combustion area of ​​the incinerator 1 by a fire grate 12M, which will be described later. The combustion area is an area where the materials to be incinerated are burned. The materials to be incinerated that reach the combustion area are burned and become incineration ash BA.

[0012] The gist of the present invention is that the dried body DB on which the dewatered sludge DS is piled is sent to the combustion area by the fire grate 12M as the incineration target. As described later, the dried body DB is a material having a moisture content equal to or lower than that of the sludge supplied to conventional incinerators. The dewatered sludge DS is sludge with a higher moisture content than the dried body DB and is sludge that has been subjected to a dewatering process. To add, the dewatered sludge DS is sludge that has not been subjected to a drying process.

[0013] More specifically, only a portion of the dewatered sludge DS to be incinerated is dried to a moisture content of 20-40% to form a non-adhesive dried body DB, which is then supplied onto the grate 12M. The remaining dewatered sludge DS is then supplied onto the dried body DB, thereby preventing the dewatered sludge DS from adhering to the grate 12M. According to the present invention, since only a portion of the dewatered sludge DS to be incinerated is dried, the processing volume or number of drying devices can be reduced.

[0014] Since the dewatered sludge DS is clayey and highly adhesive, it has the property of forming lumps when sent to the grate 12M. On the other hand, the dried bodies DB have almost no adhesiveness, so they do not form lumps even when sent to the grate 12M. When the dried bodies DB piled with the dewatered sludge DS are sent by the grate 12M, the dried bodies DB flow into the combustion area together with the piled up dewatered sludge DS. Therefore, the incinerator 1 can incinerate the dewatered sludge DS and the dried bodies DB together. Therefore, the sludge incineration facility 100 and the sludge incineration method of the present invention can reduce the scale (processing amount or number) of the drying device required to dry the amount of dewatered sludge DS that can be incinerated without drying treatment.

[0015] The dried body DB includes dried sludge DBS obtained by drying sludge, and dried matter DBM. Dried sludge DBS is generally produced by drying dewatered sludge DS. Dried sludge DBS often refers to sludge with a moisture content of 40% or less. The dried matter DBM is a material that is easily available to sludge incinerators, such as silica sand, or a material that can be obtained from the sludge incineration facility 200, such as incineration ash BA. In addition, the dried matter DBM may be a material that is sold as a commodity and is easily available, such as gravel, crushed stone, river sand, or mountain sand, or a material regenerated from waste, such as crushed slag.

[0016] The sludge incineration plant 100 according to the first embodiment uses dried sludge DBS as the dried bodies DB. As will be described later, the sludge incineration plant 200 according to the second embodiment uses dry matter DBM as the dried bodies DB.

[0017] The configuration of a sludge incineration facility 100 according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG.

[0018] As shown in Fig. 1, the sludge incineration facility 100 includes an incinerator 1 for incinerating materials to be incinerated, a drying device 20 for drying sludge to produce dried sludge DBS, a dried body supplying device 2 for supplying dried sludge DBS to the incinerator 1, a dewatered sludge supplying device 3 for supplying dewatered sludge DS to the incinerator 1, various sensors, and a control device 9. The various sensors are provided in the incinerator 1. Some of the various sensors may be provided in the dried body supplying device 2 and the dewatered sludge supplying device 3 in addition to the incinerator 1. The control device 9 controls the dried body supplying device 2 and the dewatered sludge supplying device 3 based on the measurement results of the various sensors.

[0019] The incinerator 1 has a primary combustion chamber 11, which is a chamber in which the material to be incinerated is burned, a conveying device 12 provided in the primary combustion chamber 11, and a secondary combustion chamber 13 provided above the primary combustion chamber 11 and connected to the primary combustion chamber 11.

[0020] The primary combustion chamber 11 has an inlet 111 for carrying the materials to be incinerated into the primary combustion chamber 11, and an outlet 112 for carrying out the incineration ash BA generated after the materials to be incinerated are burned from the primary combustion chamber 11.

[0021] The transport device 12 transports materials to be incinerated from an entrance 111 located upstream to an exit 112 located downstream.

[0022] The conveying device 12 has, in order from the upstream, a drying stage 121, a combustion stage 122, and a post-combustion stage 123. The drying stage 121 sends the incineration object carried in from the inlet 111 to the downstream combustion stage 122 while drying it with air supplied from under the grate. There are combustion areas above the combustion stage 122 and above the post-combustion stage 123. The combustion stage 122 sends the dried incineration object to the downstream post-combustion stage 123 while combusting it in the combustion area with air supplied from under the grate. The post-combustion stage 123 combusts unburned components contained in the incineration ash BA generated after the incineration object is burned in the combustion area. The incineration ash BA from which the unburned components have been burned flows toward the discharge outlet 112.

[0023] The drying stage 121, the combustion stage 122, and the post-combustion stage 123 each have a plurality of fire grates 12M that reciprocate in a direction from upstream to downstream, and a plurality of fire grates 12F that are fixed in position. Each of the fire grates 12M, 12F has a passage (not shown) through which high-temperature air for burning the sludge passes. The sludge piled up on each of the fire grates 12M, 12F is dried or burned by the air supplied from the passage.

[0024] The reciprocating grates 12M and the fixed grates 12F are arranged in a staggered manner in a stepped manner. In FIG. 1, the reciprocating grate 12M is provided at the position closest to the entrance 111. The reciprocating grate 12M sends the incineration material carried into the incinerator 1 through the entrance 111 downstream. The reciprocating grate 12M pushes the incineration material piled on the fixed grate 12F downstream. In addition, air for drying or combustion is supplied to the incineration material piled on each grate 12M, 12F from below each grate 12M, 12F. Therefore, the incineration material is sent downstream by the reciprocating grate 12M while being dried or burned.

[0025] The secondary combustion chamber 13 is provided above the drying stage 121. As a result, the high-temperature gas G generated by combustion in the combustion stage 122 and the post-combustion stage 123 passes over the drying stage 121 and flows into the secondary combustion chamber 13, as shown in Figure 1. The parts of the material to be incinerated that are exposed to the gas G become dry and therefore more easily combustible.

[0026] The dryer 20 consumes thermal energy such as high-temperature steam or hot air to dry the dewatered sludge DS. Therefore, the smaller the amount of dewatered sludge DS that needs to be dried, the smaller the scale (processing amount or number of units) of the dryer 20 can be. The dryer 20 supplies dried sludge DBS obtained by drying the dewatered sludge DS to the dried body supplying device 2.

[0027] The dried material supplying device 2 supplies dried sludge DBS to the grates 12M and 12F of the drying stage 121.

[0028] The dried material supplying device 2 has a dried sludge storage tank 22 that temporarily stores the dried sludge DBS supplied from the drying device 20, and a dust supplying device 23 that supplies the dried sludge DBS stored in the dried sludge storage tank 22 to the grates 12M and 12F of the drying stage 121.

[0029] The dust feeder 23 is a device that supplies dried sludge DBS from the carry-in entrance 111 to the grate 12M of the drying stage 121. The dust feeder 23 is, for example, a pusher-type device that pushes out the dried sludge DBS toward the grate 12M of the drying stage 121.

[0030] The dewatered sludge supplying device 3 is a device that supplies dewatered sludge DS onto the dried sludge DBS supplied to the grates 12M and 12F. The dewatered sludge supplying device 3 has a dewatered sludge storage tank 31 that temporarily stores the dewatered sludge DS, and a dispersion supplying device 32 that supplies the dewatered sludge DS stored in the dewatered sludge storage tank 31 from above onto the dried sludge DBS piled on the grates 12M and 12F.

[0031] The distributed supply device 32 distributes and supplies the dewatered sludge DS on the dried sludge DBS. Distributing and supplying the dewatered sludge DS means piling the dewatered sludge DS at a plurality of locations on the dried sludge DBS, which are spaced apart from each other. By distributing and supplying the dewatered sludge DS on the dried sludge DBS, it is possible to prevent a large amount of dewatered sludge DS from being supplied to a specific location. This prevents the layer thickness of the dewatered sludge DS from becoming thick in some places, and therefore the dewatered sludge DS can be burned uniformly in the incinerator 1, and the dewatered sludge DS can be burned completely and stably.

[0032] Preferably, the dispersion supply device 32 supplies the dewatered sludge DS on top of the dried sludge DBS piled on the reciprocating grate 12M. By piling the dewatered sludge DS on top of the sandy, almost non-adhesive dry sludge DBS, it is possible to prevent the dewatered sludge DS from adhering to the grates 12M, 12F or from being pushed by the grates 12M, 12F into large lumps.

[0033] Also preferably, the dispersion supply device 32 supplies the dewatered sludge DS onto the dried sludge DBS piled on the grate 12M constituting the drying stage 121. The dewatered sludge DS piled on the grate 12M constituting the drying stage 121 via the dried sludge DBS is exposed to the gas G generated in the combustion area. The dewatered sludge DS exposed to the gas G dries. As a result, the dewatered sludge DS exposed to the gas G becomes more combustible.

[0034] More preferably, the dispersion supply device 32 supplies the dewatered sludge DS onto the dried sludge DBS piled at the position closest to the carry-in entrance 111 as shown in Fig. 1. The position closest to the carry-in entrance 111 means the most upstream position among the positions where the layer of the dried sludge DBS is formed on the fire grate 12M. In this way, the dewatered sludge DS supplied to the incinerator 1 is exposed to the gas G for the longest period of time. Therefore, the dewatered sludge DS is easily combusted.

[0035] The dispersion feeder 32 is a plurality of screw feeders 321 as exemplified in FIG. 2, or a molding machine 323 as exemplified in FIG.

[0036] The multiple screw feeders 321 illustrated in FIG. 2 are devices that transport the dewatered sludge DS by means of a screw. Three screw feeders 321, 321, 321 are illustrated in FIG. 2. However, the number of screw feeders 321 is not limited to three, and is appropriately determined according to the amount of material to be incinerated, etc. Each screw feeder 321, 321, 321 has an outlet 322, 322, 322 for discharging the dewatered sludge DS. The outlet 322 is provided above the grate 12M of the drying stage 121. Each outlet 322, 322, 322 is disposed apart from each other. The dewatered sludge DS discharged from each screw feeder 321, 321, 321 is dispersed and supplied onto the dried sludge DBS.

[0037] Preferably, each of the screw feeders 321, 321, 321 is independent of the others, so that the amount of dewatered sludge DS supplied by each of the screw feeders 321, 321, 321 can be adjusted individually.

[0038] The molding machine 323 generates molded sludge with the shape of the dewatered sludge DS, as exemplified in FIG. 3. The shape of the molded sludge is determined appropriately according to the components contained in the dewatered sludge DS and / or the specifications of the incinerator 1. The molding machine 323 has a molded sludge discharge section 324 from which the molded sludge is discharged. There are multiple molded sludge discharge sections 324. The molded sludge discharge sections 324 are disposed at positions separated from each other. In this manner, the molding machine 323 can distribute and supply molded sludge having a shape suitable for the components contained in the dewatered sludge DS and / or the specifications of the incinerator 1 on the dried sludge DBS.

[0039] FIG. 3 shows an example of a forming machine 323. The forming machine 323 shown in FIG. 3 is a device in which dewatered sludge DS is passed between two adjacent rollers 325, 325. Each roller 325, 325 is provided with a plurality of grooves that intersect in the longitudinal direction. In the forming machine 323 shown in FIG. 3, each groove is a part that produces formed sludge and corresponds to the formed sludge discharge section 324. When the dewatered sludge DS is supplied between the two rollers 325, 325, the dewatered sludge DS is formed to fit the shape of the groove. Then, the formed sludge that has passed through each groove is distributed and supplied on the dewatered sludge DS.

[0040] Preferably, the groove of the molding machine 323 shown in Fig. 3 is aligned with the rotation direction, and the bottom of the groove has a constant width. With such a groove, the molded sludge becomes rod-shaped. When the rod-shaped molded sludge is piled on the dried sludge DBS, the distance between the molded sludge placed in adjacent positions can be increased. Therefore, it is possible to prevent a large amount of molded sludge from being piled up in a localized area on the dried sludge DBS.

[0041] In addition, it is preferable that the cross-sectional area of ​​the rod-shaped formed sludge is as small as possible. This is because rod-shaped formed sludge with a small cross-sectional area dries easily. However, in order to form rod-shaped formed sludge with a small cross-sectional area, the forming machine 323 requires a large power. Therefore, the cross-sectional area of ​​the rod-shaped formed sludge is determined by taking into consideration the balance between the amount of dewatered sludge DS and the power required to form the dewatered sludge DS. The cross-sectional area of ​​the cross section Y of the formed sludge that provides the best balance is 25 mm2 (For molded sludge with a square cross section, the length is D5mm and the width is W5mm).

[0042] The various sensors include a determination sensor for determining whether a layer of dried sludge DBS and a layer of dewatered sludge DS have been formed, and an adjustment sensor for adjusting the amount of dried sludge DBS or the amount of dewatered sludge DS supplied.

[0043] As shown in Figures 1 and 4, the determination sensor includes a dry mass sensor 4 that measures the amount of dried sludge DBS supplied to the grates 12M and 12F, and a dewatered sludge sensor 5 that measures the amount of dewatered sludge DS supplied on top of the dried sludge DBS.

[0044] Specifically, the dry material sensor 4 is a first level gauge 41 that measures the amount of dried sludge DBS supplied to the grates 12M, 12F by the height of the dried sludge DBS piled on the grates 12M, 12F, as shown in Fig. 1. Alternatively, the dry material sensor 4 may be a first supply amount recorder 42 that directly measures the amount of dried sludge DBS supplied to the grates 12M, 12F, as shown in Fig. 4.

[0045] As shown in FIG. 1, the first level gauge 41 measures the height of the layer of dried sludge DBS piled on the grates 12M, 12F upstream of the position where the dewatered sludge supplying device 3 supplies the dewatered sludge DS.

[0046] The first level gauge 41 measures the height from a reference position to the surface of the layer of the dried sludge DBS. The reference position is determined appropriately. For example, the positions of the fire grates 12M and 12F arranged under the first level gauge 41 are the reference positions.

[0047] The first level gauge 41 shown in Fig. 1 measures the height of the layer of dried sludge DBS piled up on the most upstream grate 12M among the reciprocating grates 12M. The first level gauge 41 can directly measure whether a layer of dried sludge DBS high enough to carry and flow the dewatered sludge DS has formed on the reciprocating grate 12M.

[0048] The first level gauge 41 is a non-contact sensor. The non-contact first level gauge 41 may be an ultrasonic level gauge, an electromagnetic level gauge, or a laser level gauge. The first level gauge 41 may also be a video camera that captures an image of the dried sludge DBS.

[0049] As shown in Fig. 4, the first supply amount recorder 42 is attached to the dried material supplying device 2. The first supply amount recorder 42 measures the amount of dried sludge DBS that the dried material supplying device 2 supplies to the fire grates 12M, 12F. The first supply amount recorder 42 does not need to be installed inside the incinerator 1, so installation is easier than that of the first level gauge 41.

[0050] Specifically, the dewatered sludge sensor 5 is a second level meter 51 that measures the amount of dewatered sludge DS supplied onto the dried sludge DBS by the height of the dewatered sludge DS piled on the dried sludge DBS, as shown in Fig. 1. Alternatively, the dewatered sludge sensor 5 may be a second supply amount recorder 52 that directly measures the amount of dewatered sludge DS supplied onto the dried sludge DBS, as shown in Fig. 4.

[0051] As shown in FIG. 1, the second level gauge 51 measures the height of the layer of dewatered sludge DS piled up in the dried sludge DBS downstream of the position where the dewatered sludge supplying device 3 supplies the dewatered sludge DS.

[0052] The second level gauge 51 measures the height from a reference position to the surface of the layer of dewatered sludge DS. The reference position is determined appropriately. For example, the position of the surface of the dried sludge DBS placed under the second level gauge 51 becomes the reference position. The second level gauge 51 directly measures the amount of dewatered sludge DS piled on top of the dried sludge DBS. Like the first level gauge 41, the second level gauge 51 is preferably a non-contact sensor or a video camera.

[0053] As shown in Fig. 4, the second supply amount recorder 52 is attached to the dewatered sludge supplying device 3. The second supply amount recorder 52 measures the amount of dewatered sludge DS that the dewatered sludge supplying device 3 supplies onto the dried sludge DBS. The second supply amount recorder 52 does not need to be installed inside the incinerator 1, and is therefore easier to install than the second level meter 51.

[0054] As shown in Figures 1 and 4, the adjustment sensor includes a first measuring instrument 6 for measuring the moisture content of the dried sludge DBS, a second measuring instrument 7 for measuring the moisture content of the dewatered sludge DS, and a thermometer 8 for measuring the temperature of the gas G generated by incinerating the material to be incinerated.

[0055] The first measuring instrument 6 is attached to the dried material supplying device 2. This allows the first measuring instrument 6 to measure the moisture content of the dried sludge DBS supplied to the grates 12M, 12F by the dried material supplying device 2. The first measuring instrument 6 is, for example, an infrared moisture meter. The first measuring instrument 6 may also be an electric resistance type, electric capacitance type, or microwave type moisture meter.

[0056] The second measuring instrument 7 is attached to the dewatered sludge supplying device 3. This allows the second measuring instrument 7 to measure the moisture content of the dewatered sludge DS that the dewatered sludge supplying device 3 supplies onto the dried sludge DBS. Like the first measuring instrument 6, the second measuring instrument 7 is, for example, an infrared moisture meter. The second measuring instrument 7 may also be an electrical resistance type, electrical capacitance type, or microwave type moisture meter.

[0057] The thermometer 8 is attached to the secondary combustion chamber 13. In this way, the thermometer 8 can measure the temperature of the gas G that flows from the primary combustion chamber 11 into the secondary combustion chamber 13.

[0058] The control device 9 controls the dried body supplying device 2 and the dewatered sludge supplying device 3. In detail, the control device 9 controls the dust supplying device 23 of the dried body supplying device 2 to adjust the amount of dried sludge DBS supplied to the grates 12M, 12F. The control device 9 also controls the dispersion supplying device 32 of the dewatered sludge supplying device 3 to adjust the amount of dewatered sludge DS supplied above the dried sludge DBS.

[0059] Specifically, if the dust feeder 23 is a pusher type, the control device 9 performs control to adjust the reciprocating speed of the pusher, the stroke of the pusher, and / or the interval between reciprocating movements of the pusher. If the dispersion supply device 32 is a plurality of screw feeders 321, the control device 9 performs control to adjust the rotation speed of the screw of each screw feeder 321. Also, if the dispersion supply device 32 is a molding machine 323 composed of two rollers 325, 325, the control device 9 performs control to adjust the rotation speed of the two rollers 325, 325.

[0060] The control device 9 is, for example, a device that combines a central processing unit and a memory. The central processing unit executes a program stored in the memory to control the dried material supplying device 2 and the dewatered sludge supplying device 3.

[0061] The control device 9 preferably controls the dust feeder 23 and the dispersion supply device 32 based on the measurement results of the first measuring device 6, the second measuring device 7, and the thermometer 8. Here, the approximate calorific value of the dried sludge DBS can be estimated from the moisture content of the dried sludge DBS. Also, the approximate calorific value of the dewatered sludge DS can be estimated from the moisture content of the dewatered sludge DS. In addition, the temperature of the gas G flowing from the primary combustion chamber 11 to the secondary combustion chamber 13 is an amount that represents the combustion state of the incineration object in the primary combustion chamber 11. Therefore, the control device 9 can adjust the increase or decrease in the supply amount of the dried sludge DBS and the dewatered sludge DS so that the incineration object in the primary combustion chamber 11 can be maintained in an appropriate combustion state.

[0062] For example, when the temperature of the gas G is likely to become lower than a predetermined temperature, the control device 9 controls the dust feeder 23 to increase the supply amount of dried sludge DBS, which has a large calorific value, thereby raising the temperature of the gas G. Conversely, when the temperature of the gas G is likely to become higher than a predetermined temperature, the control device 9 controls the dispersion feeder 32 to increase the supply amount of dewatered sludge DS, which has a small calorific value, thereby lowering the temperature of the gas G.

[0063] Hereinafter, the processing of the control device 9, that is, the sludge incineration method performed by the sludge incineration facility 100 will be described with reference to FIG. 1 and FIGS.

[0064] As shown in Fig. 7, in step S1, the control device 9 controls the dried material supplying device 2 to supply dried sludge DBS to the grates 12M and 12F. In detail, the control device 9 controls the operation of the dust supplying device 23. If the dust supplying device 23 is a pusher type, the control device 9 starts the reciprocating operation of the pusher. When the operation of the dust supplying device 23 starts, the dried sludge DBS is supplied onto the reciprocating grate 12M in the drying stage 121.

[0065] A part of the dry sludge DBS supplied onto the reciprocating grate 12M falls into the space SP1 created by the reciprocating motion of the grate 12M as shown in FIG. 5. The dry sludge DBS that falls from the reciprocating grate 12M is piled up on the fixed grate 12F. The dry sludge DBS piled up on the fixed grate 12F is pushed downstream by the reciprocating grate 12M. In this way, the dry sludge DBS is gradually sent downstream. In the following explanation, the reciprocating grate 12M basically performs a reciprocating motion, except in emergency situations. Therefore, the dry sludge DBS supplied to the grates 12M and 12F always flows downstream, except in exceptions.

[0066] In step S2, the control device 9 determines, based on the measurement result of the dry matter sensor 4, whether or not dried sludge DBS has been piled up on the fire grates 12M and 12F.

[0067] For example, as shown in Fig. 1, if the dry mass sensor 4 is a first level gauge 41, the control device 9 determines that dry sludge DBS has piled up on the grates 12M, 12F when the measurement result of the first level gauge 41 indicates that the layer height of the dry sludge DBS is equal to or greater than a predetermined value. The layer height of the dry sludge DBS used by the control device 9 for the determination is set based on the amount of the dry sludge DBS sent downstream that can flow when piled up with the dewatered sludge DS.

[0068] The height of the layer of dried sludge DBS is preferably equal to or greater than the height of the reciprocating grate 12M. In this way, only the dried sludge DBS flows into the space SP1 that is created when the reciprocating grate 12M pushes out the dried sludge DBS, as shown in Fig. 6. Therefore, the dewatered sludge DS can be prevented from being pushed out by the reciprocating grate 12M.

[0069] 4, if the dry material sensor 4 is a first supply amount recorder 42, when the amount of dried sludge DBS recorded by the first supply amount recorder 42 becomes equal to or greater than a predetermined amount, the control device 9 determines that dried sludge DBS has been piled up on the grates 12M, 12F. The amount of dried sludge DBS is set based on the amount that the dried sludge DBS sent downstream can flow with the dewatered sludge DS piled up.

[0070] In step S2, if the controller 9 determines that the dried sludge DBS is not piled up on the grates 12M and 12F (if NO), the process by the controller 9 returns to step S1. On the other hand, in step S2, if the controller 9 determines that the dried sludge DBS is piled up on the grates 12M and 12F (if YES), the process proceeds to step S3.

[0071] In step S3, the control device 9 controls the dewatered sludge supplying device 3 to supply the dewatered sludge DS onto the dried sludge DBS. Specifically, the control device 9 operates the dispersion supplying device 32. When the dispersion supplying device 32 is composed of a plurality of screw feeders 321 as shown in Fig. 2, the control device 9 controls the rotation of the screws of the screw feeders 321. When the dispersion supplying device 32 is composed of two rollers 325, 325 as shown in Fig. 3, the control device 9 controls the rotation of the two rollers 325, 325.

[0072] In step S4, as shown in Figures 1 and 4, the grate 12M sends out the dried sludge DBS piled up with the dewatered sludge DS to the combustion area above the combustion stage 122. As a result, the dewatered sludge DS piled up on the dried sludge DBS flows following the dried sludge DBS. The dried sludge DBS and the dewatered sludge DS sent to the combustion area above the combustion stage 122 are combusted. Therefore, the sludge incineration equipment 100 can combust the material to be combusted without drying all of the dewatered sludge DS. Therefore, the sludge incineration equipment 100 can reduce the scale (processing volume and number) of the drying device required for drying by the amount of dewatered sludge DS to be combusted.

[0073] The dried sludge DBS and the dewatered sludge DS are completely combusted to produce incineration ash BA. The incineration ash BA after combustion is sent from the combustion stage 122 to the post-combustion stage 123 and then discharged from the discharge port 112 to the outside of the primary combustion chamber 11.

[0074] In step S5, the dewatered sludge sensor 5 measures the amount of dewatered sludge DS. As shown in Fig. 1, if the dewatered sludge sensor 5 is the second level gauge 51, the height of the dewatered sludge DS is measured. Also, as shown in Fig. 4, if the dewatered sludge sensor 5 is the second supply amount recorder 52, the amount of dewatered sludge DS supplied by the dewatered sludge supply device 3 to the primary combustion chamber 11 is measured.

[0075] In step S6, the control device 9 determines whether or not each measurement value is within a standard range based on the measurement result of the dried mass sensor 4 and / or the measurement result of the dewatered sludge sensor 5. The standard range is an allowable range of the amount of dried sludge DBS and the amount of dewatered sludge DS that allows the dried sludge DBS piled with the dewatered sludge DS to maintain its fluidity.

[0076] In step S6, if the control device 9 determines that the measured values ​​of the amount of dried sludge DBS and the measured values ​​of the amount of dewatered sludge DS are within the standard range (YES), the process by the control device 9 proceeds to step S8. On the other hand, in step S6, if the control device 9 determines that the measured values ​​of the amount of dried sludge DBS and the measured values ​​of the amount of dewatered sludge DS are not within the standard range (NO), the process by the control device 9 proceeds to step S7.

[0077] In step S7, the control device 9 performs control to adjust the amount of dried sludge DBS supplied by the dried body supply device 2 and the amount of dewatered sludge DS supplied by the dewatered sludge supply device 3. As a result, the amount of dried sludge DBS supplied to the grates 12M and 12F and the amount of dewatered sludge DS piled up on the dried sludge DBS are each adjusted, and each measurement value falls within the reference range. If the dust feeder 23 is a pusher type, the control device 9 performs control to adjust the reciprocating speed of the pusher. Similarly, if the dispersion supply device 32 is a plurality of screw feeders 321, the control device 9 performs control to adjust the rotation speed of the screw feeder 321. Also, if the dispersion supply device 32 is a device composed of two rollers 325, 325, the control device 9 performs control to adjust the rotation speed of the two rollers 325, 325.

[0078] 8, in step S8, the first measuring instrument 6 measures the moisture content of the dried sludge DBS. The measurement result of the moisture content of the dried sludge DBS is output from the first measuring instrument 6 to the control device 9.

[0079] In step S9, the second measuring instrument 7 measures the moisture content of the dewatered sludge DS. The measurement result of the moisture content of the dewatered sludge DS is output from the second measuring instrument 7 to the control device 9.

[0080] In step S10, the thermometer 8 measures the temperature of the gas G flowing from the primary combustion chamber 11 to the secondary combustion chamber 13. The measurement result of the temperature of the gas G is output from the thermometer 8 to the control device 9.

[0081] In step S11, the control device 9 controls the dust feeder 23 and the dispersion supply device 32 based on the measurement results of the moisture content of the dried sludge DBS, the measurement results of the moisture content of the dewatered sludge DS, and the measurement results of the temperature of the gas G. In this way, the combustion state in the combustion area is maintained in an appropriate state. Specifically, when the temperature of the thermometer 8 indicates a value lower than the reference value, the control device 9 adjusts to increase the supply amount of the dried sludge DBS. When the temperature of the thermometer 8 indicates a value higher than the reference value, the control device 9 adjusts to increase the supply amount of the dewatered sludge DS. Therefore, the control device 9 can supply the dried sludge DBS and the dewatered sludge DS to the primary combustion chamber 11 so as to maintain an appropriate combustion state.

[0082] According to the sludge incineration method described above, the moisture content of the incineration target, which is the combined dried sludge DBS and dewatered sludge DS, can be made higher than the moisture content of the incineration target brought into a conventional incinerator. As a result, the amount of incineration target that needs to be dried is reduced. Therefore, the scale (processing amount or number) of the drying device 20 for drying the incineration target can be reduced.

[0083] In detail, when dewatered sludge with a moisture content of 76-80% is carried into a conventional stoker-type sewage sludge incinerator, the dewatered sludge has a high adhesiveness, so the dewatered sludge adheres to the grate or becomes large lumps, making it difficult to completely burn the dewatered sludge. To solve this problem, the dewatered sludge is dried to a moisture content of 20-40% in a drying device, and the dried sludge with almost no adhesiveness is carried into the stoker-type incinerator. However, a problem occurs in that a large-scale drying device is required to dry the dewatered sludge to a moisture content of 20-40% in a drying device.

[0084] According to the incinerator 1 of the present invention, even if the sludge has a moisture content of 40 to 80%, the sludge to be incinerated can be completely burned without adhering to the fire grates 12M and 12F or becoming large lumps. Specifically, only a part of the dewatered sludge DS to be incinerated is dried to a moisture content of 20 to 40% to form a dry body DB with low adhesion, and this is supplied onto the fire grates 12M and 12F. Then, the remaining dewatered sludge DS is supplied onto the dry body DB, thereby preventing the dewatered sludge DS from adhering to the fire grates 12M and 12F. Therefore, since only a part of the dewatered sludge DS to be incinerated is dried, the scale (processing amount or number) of the drying device 20 can be reduced.

[0085] The moisture content of the sludge to be incinerated, or the weight ratio of dried sludge DBS and dewatered sludge DS, varies depending on the sludge incineration method and / or the moisture content of the dewatered sludge DS. Here, the moisture content of the sludge to be incinerated includes the moisture content of the materials to be incinerated, including the dried sludge DBS and the dewatered sludge DS.

[0086] Regarding the moisture content of the sludge to be incinerated, for example, if it is desired to recover thermal energy from the incineration exhaust gas and use it for heating equipment within the plant, the lower the moisture content of the sludge to be incinerated, the more thermal energy can be recovered. In this case, the moisture content of the sludge to be incinerated is preferably about 40 to 65%. On the other hand, if the energy of the incineration exhaust gas is not recovered, the higher the moisture content of the sludge to be incinerated, the smaller the scale of the drying device 20 can be. In this case, the moisture content of the sludge to be incinerated is preferably about 60 to 80%.

[0087] Regarding the weight ratio of dried sludge DBS and dewatered sludge DS, for example, if the moisture content of the dewatered sludge DS is 78% and the moisture content of the sludge to be incinerated is set to 60%, 62% of the dewatered sludge DS to be treated is dried to a moisture content of 20% in the drying device 20 before being carried into the incinerator 1. Then, the remaining 38% of the dewatered sludge DS is carried into the incinerator 1 as is, so that the moisture content of the sludge to be incinerated becomes 60%. This makes it possible to reduce the scale (size or number) of the drying devices 20 by approximately 40%.

[0088] Regarding the weight ratio of dried sludge DBS and dewatered sludge DS, for example, if the moisture content of the dewatered sludge DS is 78% and the moisture content of the sludge to be incinerated is set to 70%, 37% of the amount of dewatered sludge DS to be treated is dried to a moisture content of 20% in the drying device 20 before being carried into the incinerator 1. Then, the remaining 63% of the dewatered sludge DS is carried into the incinerator 1 as is, so that the moisture content of the sludge to be incinerated becomes 70%. This makes it possible to reduce the scale (size or number) of the drying devices 20 by approximately 60%.

[0089] In step S12, the control device 9 determines whether or not the combustion of the combustion object may be terminated. Whether or not the combustion of the combustion object may be terminated is determined based on whether or not the operator has instructed the sludge incineration facility 100 to be terminated. If the control device 9 determines that the combustion of the combustion object should not be terminated (if NO), the processing of the control device 9 returns to step S6. On the other hand, if the control device 9 determines that the combustion of the combustion object may be terminated (if YES), the control device 9 terminates the combustion of the combustion object. After this, the processing of the control device 9 ends.

[0090] The configuration of a sludge incineration facility 200 according to the second embodiment will be described with reference to FIG.

[0091] The sludge incineration plant 200 according to the second embodiment differs from the sludge incineration plant 100 according to the first embodiment in that a non-adhesive sand-like dry material DBM is used as the dried body DB. In this way, the sludge incineration plant 200 shown in Fig. 9 does not need to produce dewatered sludge DS because the dry material DBM plays the same role as the dried sludge DBS. Therefore, it is not necessary to provide a drying device 20 as shown in Fig. 1. Below, the differences between the second embodiment and the first embodiment will be mainly described.

[0092] As shown in Fig. 9, the dried material supplying device 21 of the sludge incineration facility 200 according to the second embodiment is different from the dried material supplying device 2 shown in Fig. 1. In addition, the various sensors measure the dry material DBM instead of the dried sludge DBS. Specifically, the dry material sensor 4 shown in Fig. 9 measures the amount of the dry material DBM. Note that the sludge incineration facility 200 shown in Fig. 9 does not necessarily require an adjustment sensor.

[0093] The dried body supplying apparatus 21 shown in Fig. 9 includes a dried body storage tank 25 for temporarily storing dried body DBM, instead of the dried sludge storage tank 22 shown in Fig. 1. The dust feeding apparatus 23 supplies dried body DBM to the grates 12M and 12F of the drying stage 121, instead of the dried sludge DBS shown in Fig. 1. If the dried body DB is the dried body DBM, there is no need to perform a drying process for the dewatered sludge DS. Therefore, the dried body supplying apparatus 21 shown in Fig. 9 does not require the drying apparatus 20, unlike the dried body supplying apparatus 2 shown in Fig. 1. Therefore, the dried body supplying apparatus 21 shown in Fig. 9 can reduce the space required for installation and can reduce the cost required for installing the dried body supplying apparatus 21.

[0094] FIG. 10 shows the process of the control device 9 shown in FIG. 9, that is, the sludge incineration method performed by the sludge incineration facility 200 according to the second embodiment.

[0095] As shown in Fig. 10, the sludge incineration method shown in Fig. 9 has steps P1 to P8. The only difference between Fig. 10 and Fig. 7 and Fig. 8 is that the dried sludge DBS is replaced by dry material DBM. Steps P1 to P7 shown in Fig. 10 correspond to steps S1 to S7 shown in Fig. 7, respectively. Step P8 shown in Fig. 10 corresponds to step S12 shown in Fig. 8. In the sludge incineration method shown in Fig. 10, the dried material DBM plays the same role as the dried sludge DBS, so there is no need to produce dewatered sludge DS. Therefore, there is no need to provide a drying device 20 as shown in Fig. 1.

[0096] However, the embodiment is illustrative in all respects and is not restrictive. In the embodiment, air is used for drying and burning sludge in the incinerator, but the oxygen concentration in the air may be changed within a range that does not cause any problems, and a mixed gas containing other components may be used instead of air. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include the meaning equivalent to the claims and all modifications within the scope. Configurations other than those described as the embodiments for carrying out the invention are optional configurations and can be deleted and modified as appropriate. [Explanation of symbols]

[0097] 1 Incinerator 2 Dry material supply device 3. Dewatered sludge supply device 4 Dry body sensor 5. Dewatered sludge sensor 6. First Measuring Instrument 7. Second measuring instrument 8 Thermometer 9. Control Device 20 Drying equipment 21 Dry material supply device 23 Dust Feeding Device 32 Distributed feeding device 321 Screw feeder 322 Outlet 323 Molding machine 12M grate 12F Grate 100 Sludge incineration facility 200 Sludge incineration facility DB Dry Body DS Dewatered sludge DBS dried sludge

Claims

1. A sludge incineration facility that sends out sludge from upstream to downstream and incinerates the sludge, A grate that moves back and forth in a direction from upstream to downstream; A dried body supplying device that supplies dried bodies to the grate; a dewatered sludge supplying device for supplying dewatered sludge having a moisture content higher than that of the dry body on the dry body supplied to the grate; A dry matter sensor for measuring the amount of dry matter supplied to the grate; a control device that controls the dewatered sludge supply device so as to supply the dewatered sludge when the amount of the dry body loaded on the grate is measured by the dry body sensor; A sludge incineration facility characterized in that the grate sends the dried body on which the dewatered sludge is piled to an area where the dried body and the dewatered sludge are combusted.

2. 2. The sludge incineration facility according to claim 1, wherein the dewatered sludge supplying device has a dispersing and supplying device that distributes the dewatered sludge onto the dry body.

3. The dispersion feed device is a plurality of screw feeders, The screw feeder has a discharge port for discharging the dewatered sludge, 3. The sludge incineration facility according to claim 2, wherein the discharge outlets of the screw feeders are arranged apart from each other.

4. The dispersion supply device is a molding machine that produces molded sludge by adjusting the shape of the dewatered sludge, 3. The sludge incineration facility according to claim 2, wherein the molding machine has a plurality of molded sludge discharge sections through which the molded sludge is discharged.

5. Further comprising a drying device for drying the sludge, 5. The sludge incineration facility according to claim 1, wherein the drying device supplies the dried sludge obtained by drying the sludge as the dried body to the dried body supplying device.

6. A first measuring device for measuring the moisture content of the dried sludge; A second measuring device for measuring the moisture content of the dewatered sludge; a thermometer for measuring the temperature of gas discharged by burning the dried sludge and the dewatered sludge; The control device includes: The sludge incineration equipment described in claim 5, characterized in that the dried body supplying device is controlled to adjust the amount of dried sludge supplied, and the dewatered sludge supplying device is controlled to adjust the amount of dewatered sludge supplied, based on the measurement results of the first measuring instrument, the measurement results of the second measuring instrument, and the measurement results of the thermometer.

7. A sludge incineration method for incinerating sludge while sending the sludge from upstream to downstream, comprising: Providing a dry mass; Supplying dewatered sludge having a moisture content higher than that of the dry body on the dry body; A step of sending the dried body on which the dewatered sludge is piled from upstream to downstream; and burning the dried body and the dewatered sludge sent downstream.

8. The step of supplying dewatered sludge includes:

8. A sludge incineration method according to claim 7, further comprising a step of dispersing and supplying the dewatered sludge onto the dried body.

9. The step of supplying dewatered sludge includes: A step of forming a plurality of shaped sludges by adjusting the shape of the dewatered sludge; 8. The sludge incineration method according to claim 7, further comprising a step of dispersing and supplying the plurality of formed sludge pieces onto the dried body.

10. The sludge incineration method according to any one of claims 7 to 9, further comprising a step of drying the sludge to obtain dried sludge as the dried body.

11. Measuring the moisture content of the dried sludge; Measuring the moisture content of the dewatered sludge; measuring the temperature of gas discharged by combusting the dried sludge and the dewatered sludge; The sludge incineration method described in claim 10, further comprising a step of adjusting the amount of the dried sludge supplied and the amount of the dewatered sludge supplied based on the moisture content of the dried sludge, the moisture content of the dewatered sludge, and the temperature of the gas.

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